1. Field of the Invention
This invention is directed to a universal bag-making machine which has a web of bag material continuously moving therethrough and has an operations station at which the web is held or caused to be stationary for any selected bag making operation on the web.
2. Description of the Prior Art
Machinery is known for the making of bags out of tubes of synthetic polymer composition material, such as polyethylene and similar polymers. The material is either in flat form, which is folded and joined at the open edge, or is extruded as tubular material. Once tubular, all that is necessary is to join the sides of the tube at selected locations to close each bag bottom and to cut or perforate below the bottom to separate the bags from the continuous web. When the bags are to be wound, it is preferable to simply perforate and rely upon a subsequent step for separation of the bags.
The sealing and perforation step can be accomplished by flying equipment which moves with the web, but this is inconvenient because the operating equipment would then need to be designed to operate under accelerational loads. Furthermore, connections to such moving parts are more difficult. Thus, the flying equipment has been an unsatisfactory solution to the problem.
Furthermore, present bag-making equipment is designed so that each unit makes only one type and size of bag. There is no opportunity for bag size adjustments or changes in operations or bag type. Present equipment is efficient, but not flexible or universal.